A dynamic-mode atomic force microscope (dynamic AFM, dynamic atomic force microscope) is a probe microscope for observing the structure of a surface on micro-scale to nano-scale by mechanically vibrating, in resonation, a plate spring, referred to as a cantilever, having a probe at its end. Because the interaction forces acting between the probe and the surface are nonlinear, it is often hard to understand the physical meaning of a change in measured amplitude or a frequency shift. This tendency becomes eminent when the probe hits the surface.
Conventionally, the dynamics of the probe (or cantilever) of the dynamic AFM is simulated to explain the results of AFM measurement performed by an experiment group. The equation of motion of the probe is solved numerically and compared with spectroscopy of an amplitude “a” or a trajectory in the phase space to obtain theoretical interpretations (refer to non-patent documents 1 and 2, for instance). Non-patent document 1 shows the spectroscopy of an amplitude “a” in FIG. 2, and non-patent document 2 shows the relationship between a displacement “u” and a time derivative du/dτ in FIG. 2.
Non-patent document 1: B. Anczykowski, D. Kruger, and H. Fuchs, Phys. Rev. B53, 15485-15488, 1996 Non-patent document 2: N. Sasaki, et al., Appl. Phys. A66, S287-291, 1998.